The mode and tempo of extinctions and extirpations after the first contact phase of human settlements is a widely debated topic. As the last major landmass to be settled by humans, New Zealand offers a unique lens through which to study interactions of people and biota. By analyzing ancient DNA from more than 5,000 nondiagnostic and fragmented bones from 38 subfossil assemblages, we describe species and patterns that have been missed by morphological approaches. We report the identification of five species of whale from an archaeological context in New Zealand and describe the prehistoric kākāpō population structure. Taken together, this study demonstrates insights into subsistence practices and extinction processes and demonstrates the value of genetic analyses of fossil assemblages.